代码: SEQUENCE create or replace trigger bef_ins_t_country_define before insert on t_country_define referencing old as old new as new for each row begin select s_country_id.nextval into :new.country_id from dual; end; /

或: 代码: SELECT * FROM CAT WHERE ROWNUM<=N2 MINUS SELECT * FROM CAT WHERE ROWNUM B. SELECT TABLE_NAME,TABLE_TYPE FROM ( SELECT ROWNUM ROWSEQ,TABLE_NAME,TABLE_TYPE FROM CAT ORDER BY TABLE_TYPE) WHERE ROWSEQ BETWEEN N1+1 AND N2;